The Impact of Inlet Structure on Stratification Performance in Thermal Storage Tanks: A Study through Simulation and Experimental Analysis

Abstract

Thermal storage tanks are the most widely used devices for thermodynamic storage. Their stratification performance is a key factor in determining their effectiveness. In this study, a structure was proposed to improve the thermal stratification of an elbow-type thermal storage tank. An experimental study was conducted on its exothermic properties for applications in hot water storage tanks. An experimental analysis was performed to investigate the exothermic properties of the proposed structure, and the results were compared with those obtained from simulations using CFD (ANSYS 19.1) software. To investigate the effect of thermal stratification on the water inlet structure, the Richardson number, hot water output rate, and MIX number of the elbow inlet structure were compared with those of the water distributor inlet structure. The results show that the MIX numbers corresponding to the inlet structures of the two types of tanks, the elbow and water distributor types, are not very different. These values were almost identical to the Richardson numbers. Under the same working conditions, the hot water output rate was 84.90% for the elbow inlet structure and 76.39% for the water distributor inlet structure. In conclusion, elbow-type water inlet structures are easy to install, and the manufacturing process is simplified.